Setting Up Ultra-Small or Ultra-Thin Discrete Components for Easy Assembly

ABSTRACT

Among other things a method including releasing a discrete component from an interim handle and depositing a discrete component on a handle substrate, attaching the handle substrate to the discrete component, and removing the handle substrate from the discrete component.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 16/726,474, filed on Dec. 24, 2019, which is a divisionalapplication of U.S. application Ser. No. 15/501,330, filed on Feb. 2,2017 (issued as U.S. patent Ser. No. 10/529,614 on Jan. 7, 2020), whichis a 371 application of PCT/US2015/043550, filed on Aug. 4, 2015, andclaims the benefit of U.S. Provisional Application Ser. No. 62/033,595,filed on Aug. 5, 2014, and of U.S. Provisional Application Ser. No.62/060,928, filed on Oct. 7, 2014, which are each incorporated byreference herein.

BACKGROUND

This description relates generally to setting up ultra-small orultra-thin discrete components for easy assembly.

Known assembly processes automate transferring items from one place toanother using robotic pick-and-place systems.

SUMMARY

Methods for setting up ultra-small or ultra-thin discrete components foreasy pick and place in integrated circuit packaging are contemplated asdisclosed in U.S. Application No. 62/033,595 filed on Aug. 5, 2014,which is incorporated here by reference in its entirety.

In general, in an aspect, a method includes releasing a discretecomponent from a carrier and depositing a discrete component on a handlesubstrate, the discrete component having an ultra-thin, an ultra-small,or an ultra-thin and ultra-small configuration, the handle substratehaving a thickness of at least 50 microns and at least one side lengthof at least 300 microns. Implementations may include one or acombination of any two or more of the following features. The method mayalso include a release layer to the handle substrate such that thediscrete component is releasably attached to the release layer. Therelease layer is a thermally sensitive material. The release layer is anultraviolet (“UV”) light sensitive material. The release layer includesa first layer and a second layer. The first layer is attached to thehandle and a second layer oriented for discrete component deposition.The second layer is parallel to the first layer. The second layer is UVsensitive. The second layer is thermally sensitive. The first layer is apermanent adhesive. The thermal sensitivity of the second layer causes adecrease in an adhesive strength in response to an application ofthermal energy. The thermal sensitivity of the second layer causes anincrease in an adhesive strength in response to an application ofthermal energy. The UV light sensitivity causes an increase in adhesivestrength in response to an application of UV light or causes a decreasein adhesive strength in response to an application of UV light. Themethod includes transferring the discrete component on the handlesubstrate to contact a device substrate. The method includes releasingthe discrete component from the handle substrate to deposit the discretecomponent onto the device substrate. Depositing the discrete componentonto the device substrate includes bonding the discrete component to thedevice substrate. Releasing the discrete component from the handle iscontemporaneous with bonding the discrete component to the devicesubstrate. Releasing the discrete component from the handle is inresponse to the bonding the discrete component to the device substrate.Releasing the discrete component from the handle is caused by thebonding the discrete component to the device substrate. Releasing thediscrete component from the handle is completed after bonding thediscrete component to the device substrate. The discrete component isreleased from the handle through the bonding with the device substrate.Bonding further includes delivering thermal energy or energy of UV lightto both bond the discrete component with the substrate and release thediscrete component from the handle. The handle substrate remains incontact with the device substrate upon release of the handle substratefrom the discrete component. The method further includes removing thehandle substrate from the discrete component. Removing the handlesubstrate can include applying at least one of the following: a brush, ablade, compressed air, a vacuum force, a vibration, or gravity force, orany combination of two or more of them. The handle substrate includes athickness of between 49 and 801 microns, 100-800 microns, and/or 300 and800 microns. The handle substrate includes at least one side between 400and 600 microns long.

In general, in an aspect, an apparatus includes a discrete componenthaving an ultra-thin, an ultra-small, or an ultra-thin and ultra-smallconfiguration and a handle substrate releasably attached to the discretecomponent, the handle and the discrete component having a configurationthat is thicker and broader than the discrete component

Implementations may include one or a combination of any two or more ofthe following features. The apparatus also includes a release layerattached to the handle substrate such that the discrete component isreleasably attached to the release layer. The release layer is athermally sensitive material. The release layer is an ultraviolet lightsensitive material. The release layer includes a first layer and asecond layer. The release layer includes a first layer attached to thehandle and a second layer oriented for discrete component deposition.The second layer is parallel to the first layer. The second layer is UVsensitive. The second layer is thermally sensitive. The first layer issensitive permanent adhesive. The thermal sensitivity of the secondlayer causes a decrease in an adhesive strength in response to heatexceeding a thermal parameter of the adhesive. The thermal sensitivityof the second layer causes an increase in an adhesive strength inresponse to heat exceeding a thermal parameter of the adhesive. The UVlight sensitivity causes an increase in adhesive strength in response toan application of UV light. The UV light sensitivity causes a decreasein adhesive strength in response to the application of UV light. Thehandle substrate includes a thickness of between 49 and 801 microns. Thehandle substrate includes at least one side between 100 and 800 micronslong. The handle substrate includes at least one side between 300 and800 microns long. The handle substrate includes at least one sidebetween 400 and 600 microns long.

In general, in an aspect, a method includes applying a process step tocause a material between a surface of an ultra-thin, an ultra-small, oran ultra-thin and ultra-small discrete component and a substrate towhich the ultra-thin and ultra-small discrete component is to beattached, to change to a state in which the material holds theultra-thin and ultra-small discrete component on the substrate. Theprocessing step simultaneously causing a material that temporarily holdsan opposite surface of the ultra-thin and ultra-small discrete componenton a handle that is being held by a chuck of a pick and place tool, tochange to a state in which the material no longer holds the ultra-thinand ultra-small discrete component on the handle. The method includescausing the change in state includes delivering thermal energy, UVlight, or both. The material that temporarily holds an opposite surfaceof the discrete component on a handle substrate includes a release layerincluding a first layer and a second layer. The material thattemporarily holds an opposite surface of the discrete component on ahandle substrate includes a release layer including a first layerattached to the handle and a second layer that temporarily holds thediscrete component. The release layer is a thermally sensitive material.The release layer is a UV light sensitive material. The second layer isparallel to the first layer. The first layer is permanent adhesive, andthe second layer is thermally sensitive. The thermal sensitivity of thesecond layer causes a decrease in an adhesive strength in response to anapplication of thermal energy. The thermal sensitivity of the secondlayer causes an increase in an adhesive strength in response anapplication of thermal energy. The UV light sensitivity causes anincrease in an adhesive strength in response to the application of a UVlight. The UV light sensitivity causes a decrease in an adhesivestrength in response to an application of UV light. The handle includesa thickness of between 49 and 801 microns. The handle includes at leastone side between 100 and 600 microns long. The handle includes at leastone side between 300 and 800 microns long. The handle includes at leastone side between 400 and 600 microns long.

In general, in an aspect, a method includes depositing an ultra-thinwafer onto a handle substrate; and releasing a discrete component fromthe ultra-thin wafer, the discrete component having an ultra-thinconfiguration, handle substrate having a thickness of at least 50microns.

Implementations may include one or a combination of any two or more ofthe following features.

The method also includes attaching a release layer to the handlesubstrate such that the ultra-thin wafer is releasably attached to therelease layer. Releasing the discrete component includes dicing theultra-thin wafer. Dicing the ultra-wafer further includes dicing thehandle substrate to form a diced-handle substrate such that the discretecomponent is releasably attached to the handle substrate. The discretecomponent is sized to cover the surface of the diced-handle substrate.The release layer is a thermally sensitive material. The release layeris an ultraviolet light sensitive material. The release layer includes afirst and a second layer. The release layer includes a first layerattached to handle and a second layer oriented for discrete componentdeposition. The second layer is parallel to the first layer. The secondlayer is UV sensitive. The second layer is thermally sensitive. Thefirst layer is permanent adhesive. The thermal sensitivity of the secondlayer causes a decrease in an adhesive strength in response to anapplication of thermal energy. The thermal sensitivity of the secondlayer causes an increase in an adhesive strength in response to anapplication of thermal energy. The UV light sensitivity causes anincrease in adhesive strength in response to an application of UV light.The UV light sensitivity causes a decrease in adhesive strength inresponse to an application of UV light. The method also includingtransferring the discrete component on the handle substrate to contact adevice substrate. The method also including releasing the discretecomponent from the handle substrate to deposit the discrete componentonto the device substrate. Depositing the discrete component onto thedevice substrate includes bonding the discrete component to the devicesubstrate. Releasing the discrete component from the handle iscontemporaneous with bonding the discrete component to the devicesubstrate. Releasing the discrete component from the handle is inresponse to the bonding the discrete component to the device substrate.Releasing the discrete component from the handle is caused by thebonding the discrete component to the device substrate. Releasing thediscrete component from the handle is completed after bonding thediscrete component to the device substrate. The discrete component isreleased from the handle through the bonding with the device substrate.The bonding further includes delivering thermal energy or UV-light toboth bond the discrete component with the substrate and release thediscrete component from the handle. The handle substrate includes athickness of between 49 and 801 microns. The handle substrate remains incontact with the device substrate upon release of the handle substratefrom the discrete component. The method further includes removing thehandle substrate from the discrete component. Removing the handlesubstrate can include applying at least one of the following: a brush, ablade, compressed air, a vacuum force, a vibration, liquid jet,electrostatic, electromagnetic force or gravity force, or anycombination of two or more of them. The handle includes at least oneside between 100 and 600 microns long.

The handle includes at least one side between 300 and 800 microns long.The handle includes at least one side between 400 and 600 microns long.

In general, in an aspect, an apparatus includes a discrete componenthaving an ultra-thin configuration and a handle substrate releasablyattached to the discrete component, the handle and the discretecomponent having a configuration that is thicker than the discretecomponent.

Implementations may include one or a combination of any two or more ofthe following features. The apparatus also includes a release layerattached to the handle substrate such that the discrete component isreleasably attached to the release layer. The release layer is athermally sensitive material. The release layer is an ultraviolet lightsensitive material. The release layer includes a first layer and asecond layer. The release layer includes a first layer attached to thehandle and a second layer oriented for discrete component deposition.The second layer is parallel to the first layer. The second layer is UVsensitive. The second layer is thermally sensitive. The first layer issensitive permanent adhesive. The thermal sensitivity of the secondlayer causes a decrease in an adhesive strength in response to heatexceeding a thermal parameter of the adhesive. The thermal sensitivityof the second layer causes an increase in an adhesive strength inresponse to heat exceeding a thermal parameter of the adhesive. The UVlight sensitivity causes an increase in adhesive strength in response toan application of UV light. The UV light sensitivity causes a decreasein adhesive strength in response to the application of UV light. Thehandle substrate includes a thickness of between 49 and 801 microns. Thehandle substrate includes at least one side between 100 and 800 micronslong. The handle substrate includes at least one side between 300 and800 microns long. The handle substrate includes at least one sidebetween 400 and 600 microns long.

In general, in an aspect, a method includes applying a process step tocause a material between a surface of an ultra-thin discrete componentand a substrate to which the ultra-thin discrete component is to beattached, to change to a state in which the material holds the discretecomponent on the substrate. The processing step simultaneously causing amaterial that temporarily holds an opposite surface of the ultra-thindiscrete component on a handle that is being held by a chuck of a pickand place tool, to change to a state in which the material no longerholds the discrete component on the handle.

Implementations may include one or a combination of any two or more ofthe following features. The method includes causing the change in stateincludes delivering thermal energy, UV light, or both. The material thattemporarily holds an opposite surface of the discrete component on ahandle substrate includes a release layer including a first layer and asecond layer. The material that temporarily holds an opposite surface ofthe discrete component on a handle substrate includes a release layerincluding a first layer attached to the handle and a second layer thattemporarily holds the discrete component. The release layer is athermally sensitive material. The release layer is a UV light sensitivematerial. The second layer is parallel to the first layer. The firstlayer is permanent adhesive, and the second layer is thermallysensitive. The second layer is UV sensitive. The second layer isthermally sensitive. The thermal sensitivity of the second layer causesa decrease in an adhesive strength in response to an application ofthermal energy. The thermal sensitivity of the second layer causes anincrease in an adhesive strength in response an application of thermalenergy. The UV light sensitivity causes an increase in an adhesivestrength in response to the application of a UV light. The UV lightsensitivity causes a decrease in an adhesive strength in response to anapplication of UV light. The handle includes a thickness of between 49and 801 microns. The handle includes at least one side between 100 and600 microns long. The handle includes at least one side between 300 and800 microns long. The handle includes at least one side between 400 and600 microns long.

In general, in an aspect, a method includes using a releasable layer toattach a handle substrate to a discrete component, and while the handlesubstrate is attached to the discrete component, using a tool to holdthe handle substrate and cause the discrete component to contact anadhesive layer on the device substrate. The method also includes causingthe releasable layer to release the handle substrate from the discretecomponent and causing the discrete component to become attached to thedevice substrate at the adhesive layer, and withdrawing the tool fromthe handle substrate while the handle substrate remains in contact withthe discrete component through the released releasable layer.

Implementations may include one or a combination of any two or more ofthe following features:

The method includes removing the handle substrate from contact with thediscrete component. Removing the handle substrate from contact with thediscrete component includes applying at least one of the following: abrush, a blade, compressed air, a vacuum force, a vibration, or gravityforce, or a combination of any two or more of them. The releasable layeris a thermally sensitive material. The releasable layer is anultraviolet light sensitive material. The releasable layer comprises afirst and a second layer. The releasable layer comprises a first layerattached to handle and a second layer oriented for discrete componentdeposition. The second layer is parallel to the first layer. The secondlayer is UV sensitive. The second layer is thermally sensitive. Thefirst layer is permanent adhesive. The thermal sensitivity of the secondlayer causes a decrease in an adhesive strength in response to anapplication of thermal energy. The thermal sensitivity of the secondlayer causes an increase in an adhesive strength in response to anapplication of thermal energy. The UV light sensitivity causes anincrease in adhesive strength in response to an application of UV light.The UV light sensitivity causes a decrease in adhesive strength inresponse to an application of UV light. Releasing the discrete componentfrom the handle is contemporaneous with attaching the discrete componentto the device substrate. Releasing the discrete component from thehandle is in response to attaching the discrete component to the devicesubstrate. Releasing the discrete component from the handle is caused bythe attaching the discrete component to the device substrate. Releasingthe discrete component from the handle is completed after attaching thediscrete component to the device substrate. The discrete component isreleased from the handle through attaching the discrete component to thedevice substrate.

We describe here, among other things, new ways to package ultra-smalland/or ultra-thin discrete components, for example, ultra-small and/orultra-thin semiconductor dies that include integrated circuits that aretemporarily attached to handle substrates such that the resultingassembly is compatible with standard electronics packaging equipment,for example, pick-and-place die bonders and other chip assemblyequipment. Among other things, the methods and products that we describecan be relatively simple, inexpensive, effective, and compatible withcurrent systems. In that respect, these methods and products will opennew markets and expand current markets for technology including low-costelectronic devices.

We use the term discrete component broadly to include, for example, anyunit that is to become part of a product or electronic device, forexample, electronic, electromechanical, or optoelectronic components,modules, or systems, for example any semiconductor material having acircuit formed on a portion of the semiconducting material.

We use the term device substrate broadly to include, for example, anyobject that will receive the discrete component or to which the discretecomponent is assembled, for example, a higher level assembly, forexample, a product or electronic device electronic, electromechanical,or optoelectronic components, or system.

We use the term handle, handle substrate, interim handle, or interimhandle substrate broadly to include, for example, any rigid substrate,such as blank silicon wafers, glass or ceramic substrates, or substratesmade of rigid polymers or composite materials, of a thickness exceedingthe thickness of the discrete component for temporary use to transferthe discrete component to a device substrate and/or for temporary use tosupport one or more discrete components.

We use the term carrier or carrier substrate broadly to include, forexample, any material including one or more discrete components, forexample, a collection of discrete components assembled by amanufacturer, such as a wafer including one or more semiconductor dies.

With respect to a discrete component, we use the term ultra-thin broadlyto include, for example, a discrete component having a thicknessincompatible with general pick-and-place technology, for example, havinga thickness less than or equal to 50 μm.

With respect to a discrete component, we use the term ultra-smallbroadly to include, for example, a discrete component having a sizeincompatible with general pick-and-place technology, for example, havinga maximum length less than or equal to 300 μm/side.

With respect to a wafer, we use the term ultra-thin broadly to include,for example, a semiconductor wafer having a maximum thickness of lessthan or equal to 50 μm.

These and other aspects, features, implementations, and advantages canbe expressed as methods, apparatus, systems, components, means or stepsfor performing functions, and in other ways and combinations of them.

These and other aspects, features, implementations, and advantages willbecome apparent from the following description, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic side view of a handle assembly including anultra-small and ultra-thin bare discrete component and a handlesubstrate.

FIG. 2 is a schematic side view of a handle assembly including anultra-small and ultra-thin bare discrete component and a handlesubstrate.

FIG. 3 is a schematic side view of a handle assembly including anultra-thin bare discrete component and a handle substrate.

FIG. 4 is a schematic view showing an example of a discrete componentpackaging process using the handle assembly FIG. 1. The active face ofthe ultra-small and ultra-thin bare discrete component faces away fromthe device substrate.

FIG. 5 is a schematic side view of a handle substrate prior to anattachment with a discrete component.

FIG. 6 is a schematic side view of the transfer assembly and devicesubstrate assembly.

FIG. 7 is a schematic view showing another example of a discretecomponent packaging process using the handle assembly FIG. 1. The activeface of the ultra-small and ultra-thin bare discrete component facesaway from the device substrate.

FIG. 8 is a schematic side view of a handle substrate prior to anattachment with a discrete component.

FIG. 9 is a schematic side view of a multi-handle substrate assembly.

FIG. 10 is a schematic view of showing an example of discrete componentpackaging process using the handle assembly FIG. 2. The active face ofthe ultra-small and ultra-thin bare discrete component faces toward thedevice substrate.

FIG. 11 is a schematic side view of a transfer assembly and devicesubstrate assembly.

FIG. 12 is a schematic side view of a handle substrate prior to anattachment with a discrete component.

FIG. 13 is a schematic view showing an example of a discrete componentpackaging process using the handle assembly FIG. 3. The active face ofthe ultra-thin bare discrete component faces toward the devicesubstrate.

FIG. 14 is a schematic side view of a transfer assembly and devicesubstrate assembly.

FIG. 15 is a schematic view showing an example of a process for use withthe discrete component packaging process of FIG. 13.

DETAILED DESCRIPTION

We describe herein, among other things, new ways to package highlyflexible and/or tiny (for example, imperceptible) discrete components.Such flexible and imperceptible discrete components are ultra-thinand/or ultra-small and provide the flexibility and low cost beneficialto a wide range of applications, but are also currently incompatiblewith conventional packaging techniques, e.g., pick-and-place equipment.Among other things, the methods and products we describe herein areoptimized to handle such ultra-thin and/or ultra-small discretecomponents in combination with conventional pick-and place equipment. Inthat respect, these methods and products can result in a reduction inproduction cost of electronics products while supporting packaging rateshigher than those possible with conventional discrete components andpick-and-place equipment.

As shown in FIG. 1, a handle assembly 100 includes a discrete component10 and a handle substrate 108. The discrete component 10 is formed to beultra-thin having, for example, a maximum thickness of 50 μm or less, 40μm or less, 30 μm or less, 25 μm or less, 20 μm or less, 10 μm or less,and 5 μm and less, to be ultra-small having, for example, a maximumlength or width dimension less than or equal to 300 μm/side, 250μm/side, 200 μm/side, 150 μm/side and 100 μm/side, or both ultra-thinand ultra-small. As such, the dimensions of the discrete component 10render current mass integrated circuit packaging technologies, such asthe mechanical pick-and-place systems, ineffective (due to, for example,physical limitations, prohibitive costs, inefficiency, and/or lowproduction rates) if not wholly unable to package the discrete component10 or similarly sized discrete components.

The discrete component 10 includes an active face 102, which includes anintegrated circuit device. The active face 102 may also include apassivation layer (not shown). In FIG. 1, the discrete component 10 isoriented with the active face 102 facing the handle substrate 108. Sucha configuration is advantageous if the discrete component is expected tobe electrically connected to other components on the device substrateusing means and materials commonly used for such a connection, forexample, wire bonding, or tape automated bonding (TAB). The backside ofthe discrete component is bonded to the device substrates using meansand materials commonly used for such an attachment, for example, bondingwith eutectic alloys, solders, adhesives, such as conducting andnon-conducting epoxies, polyamides, and other suitable materials andmethods.

The integrated packing methods, as described below, are alternativelycapable of producing a discrete component with an alternative activeface orientation. For example, as shown in FIG. 2, a handle assembly 200can include discrete component 10 with the active face 102 exposed ororiented away from the handle substrate 108. Such an orientation isadvantageous if the discrete component 10 is expected to be electricallyconnected using the method referred to as a flip-chip assembly tocomponents, for example, conductors on a device substrate, such as thoseshown, for example in FIG. 12.

In some implementations, the handle substrate 108, for example, a blanksilicon wafer, glass, ceramics, or other inorganic or organic substance,extends beyond the discrete component 10 and is sized and configured tobe compatible with current pick-and-place systems. In some cases, one ormore circuits are placed on oversized handle substrate, and eachindividual handle is cut to size. Generally, the handle substrate 108can have a length greater than or equal to 300 μm/side, preferably400-600 μm/side, and thickness exceeding 50 μm, for example, a thicknessgreater than 50 μm, and between 100-800 μm. In these cases, whilepick-and-place systems may be unable to effectively transfer thediscrete component 10, the pick-and-place system will be able totransfer the discrete component 10 so long as the discrete component 10is attached to the sufficiently sized and configured handle substrate.As such, however, standard deployment means of the pick-and-placesystem, for example, the absence of a vacuum force, are unable torelease only the discrete component, but rather would release the handleand discrete component assembly. However, among other advantages, thecharacteristics of the attachment means and their relative relationshipto each other, particularly between the discrete component, the handlesubstrate, and the device substrate, are selectable and customizable torelease the discrete component from the handle substrate and attach itto the device substrate while the pick-and-place system retains controlover the handle substrate.

In some implementations, discrete component 30 can have a size butremain too thin for compatibility with current packaging technologies.In these cases, as shown in FIG. 3, a handle assembly 300 can includethe ultra-thin discrete component 30 attached to a handle substrate 308having a similar length to the discrete component 30. As such, thehandle assembly 300 is thick enough for compatibility with pick-andplace systems. The properties of a release layer 305 including a secondsurface 306 and a first surface 304 are generally similar to thosedescribed with reference to FIGS. 1 and 2.

In some examples, the double-sided release layer 105 is a composite ofmultiple sub-layers (e.g., a first layer and a second layer). Thedouble-sided release layer 105 and one or more of the sub-layers (ifany) can include one or more surfaces (such as an internal surface or anexternal surface). For example, referring again to FIG. 1, the discretecomponent 10 is releasably attached to the handle substrate 108 via anattachment to the release layer 105. The double-sided release layer 105includes a first surface 104 exposed to the discrete component 10 and asecond surface 106 exposed to the handle substrate 108. In someexamples, the release layer 105 is a double-sided thermal- or UV-releasetape known to be compatible with wafer mounting for wafer dicing orthinning. In such a tape, the second surface 106 includes apressure-sensitive adhesive and the first surface 104 can include aUV-release material or a thermal-release material.

Exemplary release materials that are compatible with semiconductormaterials are known, and selectable based on the desired adhesioncharacteristics.

In other examples, the release layer 105 is a single layer such that thefirst surface 104 and the second surface 106 are the same material. Suchmaterials can include, for example, spin-on thermal release materialsfor temporary wafer bond, for example, the Valtron® Heat Release EpoxySystem by Valtech or the Logitech's OCON-196 Thin Film Bonding Wax.Other exemplary thermal release materials include the Ethylene VinylAcetate (EVA) copolymer films such as the WaferGrip adhesive films byDynatex. Other exemplary materials include UV-release adhesives such aspolymers with photofunctional groups that easily change their chemicalstructure when exposed to UV light energy.

In some cases, the bond strength between the release layer 105 and thediscrete component 10 and between the release layer 105 and the handlesubstrate 108, for example, are each chosen so that when the discretecomponent 10 attaches first surface 104, the bond strength of thatattachment is weaker than the bond strength between the second surface106 and the handle substrate 108. The bond strength between the discretecomponent 10 and the first surface 104 could also be selected to beweaker than the bond strength between the discrete component 10 and adevice substrate as described below. For example, in some cases therelease layer 105 may be a material with a melting temperature lowerthan the temperature required to bond the discrete component 10 and adevice substrate as described below first. Examples include wax orsimilar materials.

In other examples, the release layer 105 is chosen such that theadhesion mechanism of the first surface 104 is independentlycontrollable relative to the attachment mechanism of the second surface106. This arrangement helps to ensure that the discrete component 10 isselectably releasable from the handle substrate 108 without necessarilyreleasing the release layer 105 from the handle substrate 108.

In other cases, for example, the release layer 105 could alternativelyor additionally include a double coated thermal release tape (such as aREVALPHA® double-coated thermal release tape by Nitto®) that includes apressure sensitive adhesive layer and a heat-release adhesive layer. Insome cases, the first surface 104 could include the heat-releaseadhesive layer while the second surface 106 could include the pressuresensitive adhesive. At least upon the application of thermal energy, thebond strength between the ultra-thin and ultra-small discrete component10 and release layer 105 could be weaker as compared with the bondstrength between the layer 106 and the handle substrate 108. As such, aforce applied to the ultra-thin and ultra-small discrete component 10away from the handle substrate, for example, a pulling and/or shearforce away from the handle substrate, could remove the ultra-thin andultra-small discrete component 10 freely from the handle 108 withoutalso removing the release layer 105, which remains attached to thehandle 108.

While the attachment means between the discrete component 10 and thehandle substrate 108 is generally described as an adhesive tape, otherarrangements would be possible. For example, vacuum or electrostaticforces could be used to form this attachment temporarily. As with therelease layer 105, the attachment means and characteristics, such asbond strength, can be selected such that the bond strength between thediscrete component and the substrate is greater than the bond strengthbetween the discrete component and the handle as the discrete componentis bonded with the substrate.

As shown in FIG. 4, a process 400 for packaging ultra-small andultra-thin discrete components can generally include discrete componentfabrication (402), wafer preparation (404-412), discrete componenttransfer (414), handle substrate attachment and dicing (416), attachmentsite preparation (418), and discrete component bonding (420).

In general, wafers bearing large numbers of discrete components can befabricated using known semiconductor techniques such as thin-filmmethods on a semiconductor material, for example, on a bulk siliconsubstrates or on layered silicon-insulator-silicon substrates (402).

The wafers can undergo partial dicing (404) using known semiconductortechniques. For example, the discrete components can be partiallyseparated by dry or wet etching, by mechanical sawing (as shown in FIG.4), or by laser micromachining. The wafer surface can be protected fromdamage with a masking film and/or a passivation layer. For example, alayer of photoresist, polymers, UV-curable polyimide, laminating films,or another suitable material can be applied and patterned using methodsof photolithography or stencil/screen printing.

The masking film can be formed in accordance with known semiconductortechniques and materials such as by applying photoresists, to the wafer.The thickness and composition of the masking film material are selectedin view of anticipated processing steps downstream from the waferfabrication. For example, the thickness and composition of the maskingfilm is selected such that that the masking film is removed, for exampleduring an etching process (410) (as described below), after the streetsare opened.

The depth of the removed material in the wafer streets can be selectedbased on the anticipated attachment process and the desired finalthickness of the assembled discrete component. For example, in adiscrete component face-up process used to form the handle assembly 100as shown in FIG. 1, the depth of wafer streets is less than the desiredfinal discrete component thickness, preferably greater than 1 μm andless than ½ of final discrete component thickness. The street width isselectable based on the method of dicing, for example, in view of theaccuracy and precision of the dicing method.

In some implementations, transferring the discrete component to a devicesubstrate can include the steps as follows.

Generally, forming an ultra-thin discrete component includes firstforming a thin wafer (406-408), for example, a thin wafer having athickness of 50 μm or less, 40 μm or less, 30 μm or less, 20 μm or less,10 μm or less, and 5 μm or less. The thickness of the wafer can bereduced or thinned based on the desired final discrete componentdimensions through known semiconductor thinning techniques, for examplemechanical grinding, chemical mechanical polishing (CMP), wet etching,atmospheric downstream plasma etching (ADP), dry chemical etching (DCE),vapor-phase etching, or any combination thereof, e.g., mechanicalgrinding followed by chemical-mechanical polishing.

In some instances, the wafer can be thinned to a thickness ofapproximately 50 μm using a mechanical grinding technique such asbackgrinding. However, in general, as the wafer thickness decreases, thewafer becomes more susceptible to damage by a mechanical grinding due tothe fragility of the thin wafer. To reduce the risk of damaging thewafer, a noncontact material removal process can be used to reduce thewafer thickness beyond what is achievable by the conventional mechanicalgrinding process. For example, to achieve a wafer thickness of 20 μm orless, a known noncontact material removal process, such as Reactive IonEtching (RIE), vapor phase etching, or any other appropriate processescan be used to produce the thin wafer.

Wafer thinning to 20 μm or less can be accomplished by only mechanicalbackside grinding followed by polishing using the proprietary 3M WaferSupport System®. In this case, the additional thinning by a noncontactmaterial removal process is not necessary.

Prior to and during the wafer thinning, the wafer can be attached to atemporary handling substrate (406-408). The temporary handling substratereleasably adheres to the wafer and is removable without damaging thewafer. For example, the temporary handling substrate can include asemiconductor tape such as a thermal-release tape (for example, ELEPHolder® by Nitto), or ultraviolet-release tape, or can include a waferhandling fixture that is configured to releasable connect to the waferusing a vacuum force, electrostatic forces, or other appropriate meansof handling thin wafers. The thermal-release tape or ultraviolet-releasetape is selected such that the tape adheres to the wafer, but isremovable either by the application of heat or UV respectively. In somecases, the temporary handling substrate can be a laser transparentinterim handle (410-412), for example, a glass interim handle using adynamic releasing layer (which we call DRL), disclosed in PCTWO2012/033147, which is incorporated here by reference in its entirety.

As discussed above, the discrete components are formed by the separationof portions of the semiconductor material from the wafer, for example,along the streets formed in the wafer. As shown in FIG. 4, individualdiscrete components can be released from the wafer using a dry etchingtechnique, for example, RIE is used (410-412). As described above, theparameters and plasma gas composition are selected such that the siliconin the streets is completely etched or removed (410) prior to etching orremoving any other mask material (412). For example, a photoresistmaterial and thickness can be selected, depending on the processparameters and plasma gas compositions if a RIE is used. In this case,the parameters and plasma gas composition are selected such that thesilicon in the streets is completely etched or removed prior to etchingor removing any other mask material. In some cases, process parametersinclude a 1:1 mix of SF₆ and O₂ as a plasma gas, pressure 13-14 Pa,power 135 W, and DC-bias 150 V. In this example, after the streets areopened, etching continues until the masking layer is completely removedfrom the discrete component surface.

Releasing the individual discrete components from the handling substratewill depend upon the handling substrate material and/or adhesivematerial used. As described above, the discrete components, for example,are mounted to a glass interim handle using a DRL layer. In this case,the discrete components can be released from the DRL using a lasertransfer method (414) without contacting the ultra-thin discretecomponent. Other methods than can handle ultra-thin discrete componentscan be used to transfer the discrete components to the handle substrate.

Referring to FIGS. 4 and 5, the discrete components can be released fromthe DRL layer and attached to a handle substrate by using a lasercontactless technology (414) for ultra-thin chips assembly (which wecall SLADT), disclosed in PCT WO2012142177, which is incorporated hereby reference in its entirety. A distance 502 between each discretecomponent 10 is selectable based on the capabilities of the wafer dicingtool, for example, kerf and precision, dimensions of the ultra-small andultra-thin discrete component 10, and dimensions of the handle 108.Suitable wafer dicing tools and/or methods include sawing, lasercutting, scribing, stealth dicing, and other known suitable methods. Insome examples, the distance 502 is greater than 50 μm, for example,inclusive of and between 50 μm and 200 μm. Prior to forming theindividual handle assemblies, for example, the handle assembly 100, oneor more discrete components 10 are released onto an oversized handlesubstrate 108 a to form an oversized handle assembly 500. In some cases,the oversized handle assembly is positioned below the glass interimhandle so that when the discrete components are released, each discretecomponent travels in a direction generally indicated by arrow 504towards a release layer 105 a, which is pre-coated, for example, usingany suitable process such as lamination or spin coating, onto the handlesubstrate 108 a. The properties of the handle substrate 108 a, therelease layer 105 a including a second surface 106 a and a first surface104 a are generally similar to those described with reference to thehandle assembly 100, with the exception of the increased size of thehandle substrate 108 a and associated release layer 105 a.

As such, in some implementations, the second surface 106 a includes apressure activated adhesive for attachment of the release layer 105 a tothe handle substrate 108 a and the first surface 104 a includes athermal-release surface or a UV release surface, for example, athermal-release layer or a UV-release layer for attaching the discretecomponent 10 to the release layer 105 a. Thus, as the discrete componentcomes into contact with the release layer 105 a, the discrete componentis releasably attached to the handle substrate 108 a, until, forexample, an application of heat or UV light.

In other examples, the release layer 105 a is a single layer such thatthe first surface 104 a and the second surface 106 a are the samematerial, for example, a thermal release adhesive or a UV-releaseadhesive.

As described elsewhere, the methods described herein are used to attachultra-thin and/or ultra-small bare discrete components to any devicesubstrate used in integrated circuit packaging, such as a printedcircuit board, plastic casing, ceramic substrate, flexible circuit, orother device substrates. Prior to attaching the discrete components to adevice substrate, for example a device substrate 604, attachment meansfor the discrete component can be provided. For example, as shown inFIG. 4, a thermally cured non-conductive discrete component attachmentmaterial (such as Ablebond 8008NC by Henkel) can be dispensed to form anadhesive surface 608 for the discrete component to attach to devicesubstrate 604 (418).

Referring to FIGS. 4 and 6 a transfer 600 to a device substrate caninclude, for example, a discrete component bonding tool 602, a handleassembly 100, and a device substrate 604. In some implementations, thediscrete component bonding tool 602 attaches to the handle substrate 108of the handle substrate assembly 100. The discrete component bondingtool 602 moves towards the device substrate and positions the discretecomponent 10 directly over the attachment surface 608 on the devicesubstrate 604. The discrete component bonding tool 602 then moves thehandle assembly 100 toward the device substrate, for example, in adirection generally show by an arrow 610, until the discrete component10 contacts the adhesive surface 608. Once contact is made, the discretecomponent bonding tool applies a force and temperature profile that cancure the adhesive on the adhesive surface 608. Because the discretecomponent 10 is attached to the handle substrate assembly through athermal-release layer, temperature profile delivered to the adhesive onthe adhesive surface 608 quickly or simultaneously weakens the adhesionbetween the discrete components 10 from the handle substrate 108. Anyremaining bond strength between the handle substrate 108 and thediscrete component 10 is insufficient to overcome the bond strengthbetween the discrete component 10 and the device substrate 604. As aresult, the discrete component 10 remains attached to the device surfaceas the discrete component bonding tool 602 and handle substrate moveaway from the device substrate. The handle substrate can subsequently bereleased from the discrete component bonding tool for disposal at adifferent location by applying a positive pressure through the discretecomponent bonding tool.

If the handle substrate includes a UV releasable layer (104) than athermal release layer, the transfer means, for example, the discretecomponent bonding tool 602, can be facilitated with a device that iscapable of emitting UV light. As with the thermal-release discretecomponent bonding tool, the UV-release discrete component bonding toolcan emit UV light with sufficient intensity to de-bond the discretecomponent from the handle. In this case, an additional heat source isrequired to bond the discrete component to the device substrate. Such aheat source can be integrated with the work table that holds the devicesubstrate.

In certain implementations, the discrete component can be bonded to thehandle substrate by a UV releasable layer while the adhesive on thedevice substrate can be a UV-cured adhesive material. In this case,emitting a UV light of a sufficient intensity, based on the chosenadhesives, can weaken the bond between the discrete component and thehandle substrate and bond the discrete component to the adhesive on thedevice substrate.

In some examples, various combinations of thermally sensitive or UVsensitive adhesives are used such that the bond between the discretecomponent and the handle substrate weakens while the bond between thediscrete component and the device substrate strengthens.

In some cases, heat or UV light are also or alternatively appliedthrough the device substrate to cure the adhesive on the devicesubstrate.

In some implementations, transferring the discrete component to a devicesubstrate can include the steps as follows.

As shown in FIG. 7, a process 700 for packaging ultra-small and/orultra-thin discrete components in a face up configuration can generallyinclude obtaining or fabricating a wafer (702), partially dicing thewafer (704), thinning the wafer (706), separating the discretecomponents from the wafer (708), transfer the discrete components fromthe wafer to an interim handle substrate (710), transfer the discretecomponents from the interim handle substrate to the handle substrate(712), bonding the discrete components to the handle substrate whileweakening the bond between the interim handle substrate and the discretecomponents (712), dividing the handle substrate into a plurality ofindividual handle substrates each including a discrete component (714),preparing the device substrate for attachment with the discretecomponent (716), picking up the handle assembly using a discretecomponent bonding tool and positioning the handle assembly over thedevice substrate to align the discrete component with the attachmentadhesive on the device substrate (718), moving the discrete componentinto contact with the attachment adhesive on the device substrate (718),emitting energy such that the bond between the discrete component andthe handle substrate weakens while the bond between the discretecomponent and the device substrate strengthens (718), moving thediscrete component bonding tool away from the device substrate while thediscrete component remains bonded to the device substrate (718), andreleasing the handle substrate from the discrete component bonding tool(718).

In general, wafers bearing large numbers of discrete components can befabricated using known semiconductor techniques such as thin-filmmethods on a semiconductor material, for example, on bulk siliconsubstrates or on layered silicon-insulator-silicon substrates (702).

During dicing (704) the wafers can undergo partial dicing using knownsemiconductor techniques. For example, the discrete components can bepartially separated by dry or wet etching, by mechanical sawing (asshown in FIG. 7), or by laser cutting. In certain cases, the wafer isdiced to form street depth equal or slightly greater than the finaldiscrete component thickness.

In some implementations, wafer thinning, discrete component separationare generally similar to the wafer thinning, and discrete componentseparation described with reference to the process 400 except for anydiscussion related to a masking film. For example, the process 700 omitsa masking film so the dry etching (708) is simply carried out until thestreets are unobstructed.

While the process of transferring the discrete components from the wafer(710) is generally similar to the process described with reference tothe process 400, here discrete components are first transferred to aninterim substrate handle 808 along a direction 812, with each discretecomponent 10 separated by a distance 802. Referring to FIG. 8, anoversized handle assembly 800 is generally similar to the oversizedhandle assembly 500, with the exception of the location of the activediscrete component face 102 and the type of release layer 805. Here, theactive discrete component face is oriented away from the interimsubstrate 808. Further, the interim substrate 808 is coated with alow-temperature adhesive heat-release tape so that when the tape isexposed to a certain temperature, the tape loses its adhesiveproperties. For example, REVALPHA 319Y-4L by Nitto® has a releasetemperature of 90° C.

Referring to FIG. 9, to transfer the discrete components from theinterim handle substrate 808 to the handle substrate 108, the interimhandle substrate 808 is placed over or stacked on the handle substrate108. In this case, the handle substrate 108 includes release layer 105including a layer 104 that heat sensitive with a higher releasetemperature, for example, REVALPHA 319Y-4H by Nitto® with a releasetemperature of 150° C., than the release temperature of the interimhandle substrate. To weaken the bond between the discrete components andthe interim handle substrate, the stack is heated to a temperaturehigher than the release temperature of the low-temperature tape butlower than the release temperature of the high-temperature tape. Theconditions result in the interim handle substrate 808 losing adhesion.As such, the interim handle substrate is freely removable. In somecases, the interim substrate assembly is also reusable.

The discrete component packaging process including preparing the devicesubstrate (716) and transferring the discrete component to the devicesubstrate (718) is generally similar to the discrete component packagingprocess described with respect to FIG. 4.

As shown in FIG. 10, a process 1000 for packaging ultra-small andultra-thin discrete components in a flip-chip configuration cangenerally include obtaining or fabricating a wafer (1002), partiallydicing the wafer (1004), thinning the wafer (1006), separating thediscrete components from the wafer (1008), transfer the discretecomponents to a handle substrate (1010) dividing the handle substrateinto a plurality of individual handle substrates each including adiscrete component (1012), preparing the device substrate for attachmentwith the discrete component (1014), picking up the handle assembly usinga discrete component bonding tool and positioning the handle assemblyover the device substrate to align the discrete component with theattachment adhesive on the device substrate (1016), moving the discretecomponent into contact with the attachment adhesive on the devicesubstrate (1016), emitting energy such that the bond between thediscrete component and the handle substrate weakens while the bondbetween the discrete component and the device substrate strengthens,(1016) moving the discrete component bonding tool away from the devicesubstrate while the discrete component remains bonded to the devicesubstrate, and releasing the handle substrate from the discretecomponent bonding tool (1016).

In general, wafers having bumped out discrete components, as required bya flip-chip configuration, are generally known. Common methods for waferbumping include stud bumping, electroless nickel-gold plating, solderballs, solder paste printing, solder electroplating, etc. While aninitial wafer having a low profile electroless nickel-gold plating iscompatible with the process described here, the creation of bumps canoccur after transferring the discrete components from the glasssubstrate (1010) and before placing the discrete components on thehandle substrate (1012).

The wafer dicing process (1004), the wafer thinning process (1006), thediscrete component separation (1008), the discrete component transfer(1010), forming individual handle substrates (1012), and discretecomponent bonding (1016) are generally similar to other methodsdiscussed above. For example, the discrete components 10 are placed onthe handle substrate 108, as shown in FIGS. 5 and 11, in the same mannerbut for the orientation of the active face 102 on the discrete component10. Here, each of the discrete components 10 are separated by a distance1202 and travel along a direction 1204.

Referring to FIGS. 10-12, the discrete component 10 is attached to thedevice substrate 608 using electrically conductive materials 1106 and anadhesive material 1108.

The types of adhesive materials and application methods depend on themethod selected to connect the discrete component electrically to theconductor traces on the device substrate. For example, conductiveadhesives in a liquid form (e.g., anisotropic conductive adhesive, ACP,for example, type 115-29 by Creative Materials) or other commonly usedmethods and materials, for example, anisotropic conductive films andpastes, isotropic conductive films and pastes, and solders can be used.The discrete component bonding generally includes picking up the handleassembly using a discrete component bonding tool and positioning thehandle assembly over the device substrate to align the discretecomponent with the attachment adhesive on the device substrate (1016),moving the discrete component into contact with the attachment adhesiveon the device substrate (1016), emitting energy such that the bondbetween the discrete component and the handle substrate weakens whilethe bond between the discrete component and the device substratestrengthens, (1016) moving the discrete component bonding tool away fromthe device substrate while the discrete component remains bonded to thedevice substrate, and releasing the handle substrate from the discretecomponent bonding tool (1016).

In certain implementations, if adhesion methods beyond ACP bonding areused, it is desirable to customize the site preparation mechanismsand/or process (1014) to accommodate for the new material.

As shown in FIG. 13, a process 1300 for packaging an ultra-thin discretecomponent in a flip-chip configuration can generally include obtainingor fabricating a wafer (1302), thinning the wafer using a mechanicalthinning process or a mechanical thinning process followed by anon-contact thinning process (1304), mounting the ultra-thin wafer to ahandle substrate (1306), separating the discrete components from thewafer (1308), preparing the device substrate for attachment with thediscrete component (1310), picking up the handle assembly using adiscrete component bonding tool and positioning the handle assembly overthe device substrate, as also shown in FIG. 14, to align the discretecomponent with the attachment adhesive on the device substrate 608,moving the discrete component into contact with the attachment adhesive604 on the device substrate 608, emitting energy such that the bondbetween the discrete component and the handle substrate weakens whilethe bond between the discrete component and the device substratestrengthens (1312), moving the discrete component bonding tool away fromthe device substrate while the discrete component remains bonded to thedevice substrate, and releasing the handle substrate from the discretecomponent bonding tool (1312).

As with other flip-chip configurations, the discrete component isattached to the device substrate 608 using electrically conductivematerials 604

Generally, the wafer formation (1302) and wafer thinning by contact ornon-contact material removal processes (1304) are generally similar toprocess described elsewhere. However, the singulation of the individualdiscrete component and sizing of the handle substrate (1308) aresomewhat streamlined in certain cases. For example, the release layer305 including a second surface 306 and a first surface 304 is appliedalong handle substrate with a thermal or UV-release layer exposed to thebackside of the ultra-thin wafer and the pressure sensitive layerattached to the handle substrate (1306). In this case, the length andwidth of the handle substrate 308 can be equal to the dimensions of theultra-thin discrete component 30. As such, the handle substrate andwafer can be simultaneously diced into the individual handle assemblies300 (1308).

As shown in FIG. 15, the processes for packaging a discrete component,as described above, can be modified as illustrated in a process 1500 forattaching a discrete component 1501 to a device substrate 1502. Forexample, the device substrate 1502 is first prepared (1310) forattaching to the discrete component 1501 by dispensing an amount ofadhesive 1505 through a dispensing tube 1507 onto the device substratesurface 1509 (including conductors 1511) at a location 1515 of thedevice substrate 1502 where the discrete location is to be attached.

The process 1500 can then generally include picking up (1502) the handleassembly 1552 (which includes the discrete component 1501, the handlesubstrate 108, the release layer 105) by applying a vacuum 1513 througha vacuum tube 1516 of a discrete component transfer tool 1508.

The transfer tool with the handle assemble is then positioned (1502)over the location 1515 of the device substrate as also shown in FIGS. 13and 14, aligning the discrete component with the attachment adhesive onthe device substrate 1502 (604 in FIG. 6). The discrete component isthen moved into contact with the attachment adhesive 1505 (608 in FIG.6) on the device substrate 1502.

After the discrete component contacts the attachment adhesive 1505 (608in FIG. 6) (which may or may not be at that moment in a somewhat fluidstate) on the device substrate 1502, the vacuum in the vacuum tube canbe broken to release the transfer tool 1508 from the handle and thetransfer tool can be moved away. Then a separate discrete componentbonding tool 1510 may be moved into contact with the discrete component.Pressure 1550 or energy 1551, e.g., thermal or UV energy, or both, thencan be applied 1517 to the discrete component 1501, the handle substrate108, the release layer 105 through a contact surface 1519 of the bondingtool 1510 into the handle and also through the handle to the bond 1521,through the bond to the discrete component 1501, and through thediscrete component 1501 to the bond 1523 with the device substrate. Thepressure or energy or both can simultaneously or in sequence cause thebond 1521 between the discrete component and the handle substrate toweaken and the bond 1523 between the discrete component and the devicesubstrate to strengthen (1504). When pressure is being applied, thepressure can operate simultaneously to weaken the bond 1521 and tostrengthen the bond 1523. When energy is being applied, in some cases,the energy must flow through the successive elements of the system sothat the weakening of bond 1521 may begin or be completed before thestrengthening of the bond 1523 begins or is completed, or the weakeningand the strengthening can occur in sequence.

In some cases the release layer 105 and the attachment adhesive areselected such that the bond 1523 between the discrete component 1501 andthe device substrate 1502 forms before the bond 1521 is formed betweenthe handle and the discrete component 1501, or the formation of the bond1523 and the bond 1521 can occur simultaneously with complete overlap intime, or the formation can overlap partly with either the bond 1523 orthe bond 1521 partly occurring earlier than or later than theoverlapping period. The formation of either the bond 1523 or the bond1521 can include a hardening or softening of a material, e.g., a waxmaterial. For example, in some cases, the release layer 105, theattachment adhesive 1505, or both the release layer 105 and theattachment adhesive 1505 may include one or more materials that softenor harden in response to an application of energy. In this case, thesoftening of the bond 1523 can occur before the hardening of the bond1521, or the softening of the bond 1523 can occur after the hardening ofthe bond 1521, or the two events can occur simultaneously with completeoverlap in time, or they can overlap but one or the other can partlyoccur earlier than or later than the overlapping period.

Once the weakening and strengthening after progresses to an appropriatedegree, the discrete component bonding tool 1510 may be removed leavingthe handle assembly (including the discrete component 1501, the handlesubstrate 108, the release layer 105) in contact with the discretecomponent, which is bonded to the device substrate 1502. While notbonded to the discrete component (because of the weakening of bond1523), the handle remains in contact with the discrete component, forexample, due to gravitational force, surface attraction force, orresidual adhesive force remaining after the debonding process, or acombination of two or more of these forces the two. The handle substratemay then be removed (1506) from the discrete component using any of avariety of separation techniques, e.g., brushing, compressed air,vacuum, vibration, liquid jet, electrostatic, electromagnetic forcereorienting the device substrate such that gravity separates the handlefrom the discrete component, or any combination of two or more of those.In general, a variety of separation techniques are contemplated, e.g.,techniques applying force, energy, contact, and any combination of twoor more of these to separate the handle substrate from the discretecomponent so long as the discrete component and/or the handle substrateare not damaged.

In some examples, the discrete transfer tool 1508 may be configured toapply a vacuum force to the handle assembly similarly to the use of thediscrete component transfer tool 602 in FIG. 6. In some examples, thediscrete transfer tool 1508 may be configured to apply pressure, heat,or UV light, or a combination of them to the handle assembly similarlyto use of the discrete component transfer tool 602 in FIG. 6.

Although FIG. 15 shows the removal of one handle assembly; the sameseparation technique or techniques may be used to remove two or morehandle assemblies at the same time. For example, multiple handlesubstrates may be arranged in proximity to each other such that a brush,a blade, an application of compressed air, an application of a vacuum,or an application of a vibrational force, or any combination of two ormore of them, may remove the two or more handle assemblies from theircorresponding discrete components.

While FIG. 15 shows an example of a process for use with the discretecomponent packaging process of FIG. 13, the process here may also besimilarly used to remove the handles with the processes shown in FIGS.4, 7, and 10.

1. (canceled)
 2. A method comprising: providing a first substrate, arelease layer attached to the first substrate, and a discrete componentattached to the release layer; providing a device substrate and anadhesive layer attached to the device substrate; and applying a stimulusto the release layer, the stimulus causing the release layer to undergoa change in state at least partially concurrently with a change in stateof the adhesive layer attached to the device substrate, in which thechange in state of the release layer is a change to a state in which therelease layer has an adhesion that is not sufficient to adhere thediscrete component to the first substrate, and in which the change instate of the adhesive layer is a change to a state in which the adhesivelayer has an adhesion that is sufficient to adhere the discretecomponent to the device substrate.
 3. The method of claim 2, in whichthe discrete component has an ultra-thin, an ultra-small, or anultra-thin and ultra-small configuration.
 4. The method of claim 2, inwhich at least one side of the first substrate has a length longer thanat least one side of the discrete component.
 5. The method of claim 2,in which applying the stimulus to the release layer comprises applyingthermal energy, UV light, or both.
 6. The method of claim 2, in whichthe stimulus causes the change in state of the adhesive layer.
 7. Themethod of claim 2, in which the discrete component comprises anintegrated circuit on a face of the discrete component in contact withthe release layer.
 8. The method of claim 2, in which the change instate of the adhesive layer comprises a curing of the adhesive layer. 9.The method of claim 2, comprising applying the stimulus by a bondingtool in contact with the first substrate.
 10. The method of claim 2,comprising applying a second stimulus through the device substrate, thesecond stimulus causing the change in state of the adhesive layer. 11.The method of claim 2, comprising applying the stimulus while thediscrete component is in contact with the adhesive layer.
 12. A methodcomprising: providing a substrate, a release layer attached to thesubstrate, and a discrete component releasably attached to the substrateby the release layer, in which the release layer comprises multiplelayers, in which a first layer of the multiple layers is a permanentadhesive and a second layer of the multiple layers is at least one ofthermally sensitive and UV light sensitive, and in which the discretecomponent has an ultra-thin, an ultra-small, or an ultra-thin andultra-small configuration; and applying a stimulus to the release layer,the stimulus causing the release layer to release the discrete componentsuch that, subsequent to being released from the release layer, thediscrete component is in contact with neither the first layer nor thesecond layer.
 13. The method of claim 12, in which the first layer ofthe release layer is attached to the substrate, and in which thediscrete component is releasably attached to the second layer of therelease layer.
 14. The method of claim 12, in which the discretecomponent has a thickness less than 50 microns.
 15. The method of claim12, in which the discrete component comprises an integrated circuit on aface of the discrete component in contact with the release layer. 16.The method of claim 12, in which applying the stimulus comprises causingthe release layer to melt.
 17. The method of claim 12, in which applyingthe stimulus comprises applying a normal force, a shear force, or anormal and shear force to the discrete component.
 18. The method ofclaim 12, in which applying the stimulus comprises applying thermalenergy, UV light, or both.
 19. The method of claim 12, in which applyingthe stimulus causes a decrease in an adhesive strength of the secondlayer of the release layer.
 20. The method of claim 12, in which therelease layer remains attached to the substrate in response to thestimulus.
 21. The method of claim 12, in which a bond strength betweenthe discrete component and the release layer is less than a bondstrength between the release layer and the substrate.